This disclosure relates to a grain turner for a tower grain dryer or the like; and in particular, to such a grain turner that is movable between a collapsed position which allows grain to flow vertically within a grain column of the dryer and an extended position which the grain turner turns the grain from the inside to the outside of the grain column and vice versa as the grain moves downwardly within the grain column.
Generally, tower grain dryers comprise a vertical tower of cylindrical or other shape. The tower has a plenum located within the tower. A burner is located within the tower dryer and one or more blowers force air heated by the burners into the plenum. The outer cylindrical wall of the plenum is perforated; and an outer, perforated cylindrical wall surrounds the plenum wall, where the outer wall and the plenum wall define a grain drying column therebetween. Typically, heated air from within the plenum is forced through the perforated plenum wall and into the grain column, and air and moisture from the grain column is exhausted to the atmosphere. In this manner, the grain in the grain column is heated and dried as the grain moves down in the grain column. As is typical in tower dryers, cool, ambient air is drawn toward the blower and the burner through the grain column so as to cool the dried grain and to recover heat from the grain.
During operation, wet grain to be dried is conveyed to the upper reaches of the tower and is evenly distributed around the grain path. As dried grain is continuously discharged from the lower end of the grain drying path, additional grain to be dried is loaded into the upper end of the drying path such that the tower dryer is a continuous flow grain dryer.
Conventionally, many of the tower grain dryers and continuous flow portable dryers now in use are so-called cross flow, column dryers. That is, as the vertical grain in the grain column is metered downwardly as controlled by metering the flow of dried grain from the bottom of the grain column, heated air is forced outwardly from the plenum through the grain path. Thus, the grain proximate the inner wall of the grain path is heated more than the grain proximately the outer wall of the dryer. The grain along the inner wall becomes over dried and the grain on the exterior of the grain path is under dried. In order to overcome this problem of uneven drying, such tower dryers are often provided with a variety of grain turning devices within the grain column that turn the grain from the inner wall to the outer wall and vice versa so as to more evenly dry the grain in the grain column. More than one of these grain turners has been used.
Grain turners (sometimes referred to as inverters) play an important role in the grain drying process of a cross flow dryer. As grain is dried, a “drying front” moves through the grain column toward the exterior of the dryer. This creates a moisture gradient from the inside (dry grain) to the outside (moist grain) of the grain mass in the column. Turners are placed in the grain column to move or mix the grain so that the resulting product is more evenly dried. A grain turner is shown in U.S. Pat. No. 6,035,544, which is incorporated by reference. This grain turner divides the grain path in a rotated 180° configuration (i.e., substantially twisted about a vertical axis) so that the grain on the outside of the grain path is exchanged with the grain on the inside of the grain path (and vice versa).
Situations exist, however, in which turners are not desired, such as when drying products such as wheat or soybeans. For these products, adequate drying is achieved by passing through the drying path. Similar to the grain, these products are conveyed to fall within the drying path. Current turners are fixed. Hence, if a farmer or grain store desires to not “turn” product in the drying path, they will have to use separate equipment. It would be desirable to provide a turner which will allow farmers, grain stores, etc. to use the same drying tower for product which must be turned, and for product which need not be turned.
Corresponding reference characters represent corresponding parts throughout the various views of the drawings.